It’s all about perspective. New performers and techs can get easily confused about stage directions. This is how they work.
When you are standing on stage looking at the audience your right is “stage right” and your left is “stage left”. When you’re in the audience looking at the stage your right is “house right” and your left is “house left”. House right and stage left are the same direction. Confusing, I know… Imagine all the fun you can have if they tell you to “exit stage right” and you fall off the stage because you’re thinking in terms of “house” direction.
Another bit of terminology that will help you be understood by stage hands, lighting techs, sound engineers and stage managers is “upstage” and “downstage”. Stages used to be “raked” or sloped with the part nearest the audiance situated closest to the ground and the part furthest away from the audience being higher.
On a raked stage everyone in the audience can see the action onstage which takes place towards the back curtain. They don’t build raked stages anymore but the terminology stuck. Consequently, if you’re going to talk about the part of the stage closest to the audience, it’s called “downstage” and if you’re discussing the part by the back wall or rear curtain it’s called “upstage”. Of course the middle of the stage is called “midstage”.
I hope this sheds a little light on things. When performers and technicians speak the same language it helps them both do a better job.